Grinding machine



Sept. 13, 1966 K. HEESEMANN GRINDING MACHINE I3 Sheets-Sheet 1 Filed June 26, 1964 Jnventor: KA RL HEE'SE/VANN Sept- 1966 K. HEESEMANN 3,271,907

GRINDING MACHINE Filed June 26, 1964 5 Sheets-Sheet 2 Fig.2

7n venfo r KARL. HEE-SEfl/M/A/ J -a WM Sept. 13, 1966 K. HEESEMANN GRINDING MACHINE 5 Sheets-Sheet 5 Filed June 26, 1964 Inventor: K A R 4. HEESEMA NN yeg United States Patent 3,271,907 GRINDING MACHINE Karl Heesemann, 54 Friedenstrasse, Rehme, via Bad ()eynhausen, Germany Filed June 26, 1964, Ser. No. 378,277 16 Claims. (Cl. 51--141) This invention relates to a grinding machine for grinding rabbets and other profiles pre-shaped by cutting shap- In the known grinding machines of this type, the abrasive band is forced from the inside into contact with the workpiece to be ground by means of an appropriately shaped press means. For grinding sharp-edged profiles such as rectangular rabbets or the like, such presser means must also be sharp-edged to accurately match with the profile to be ground. Owing to this requirement, the abrasive band is subjected to considerable wear caused by the immense friction on the sharp-edged presser means. To keep this wear within reasonable limits, it is even necessary to round the sharp edges of the presser means a little. This measure, however, results in the great inconvenience of obtaining profiles that are not fully ground out.

It is the object of the present invention to eliminate the aforementionesd disadvantages of the grinding machines in question.

To attain this object, the invention provides a grinding machine for grinding rabbets and other profiles, of the type including a circulating endless abrasive band guided over pulleys one of which is a driving pulley, which comprises in combination a supporting beam having a presser shoe mounted thereon so as to be movable transversely of the direction of movement of said abrasive band and in a direction parallel to the plane of said abrasive band, and a profiled presser member rotatably mounted in a recess in said presser shoe, said presser shoe engaging under pressure said abrasive band on the side remote from a workpiece thereby to bring said abrasive band into biased contact with a profile to be ground of said workpiece.

In a preferred embodiment of the invention, the presser shoe is provided with slide faces for engaging the abrasive band and the rotatable profiled presser member is adjustable in relation to said slide faces in the direction in which the contact pressure is exerted.

When using such a rotatable profiled presser member having a shape accurately corresponding with the profile to be ground, for example a sharp-edged rabbet, the friction produced by the abrasive band forced into the rightangled edge of the rabbet by means of the profiled presser member will cause the latter to rotate at a speed equal to the speed of the abrasive band, i.e. the hitherto disadvantageous sliding friction in the region of the sharp edge now is replaced by harmless rolling friction. Due to this feature, it is possible to use sharp-edged presser members for fully grinding out a profile in a workpiece without thereby to overstrain the abrasive band.

Thus, the wear of the abrasive band is considerably reduced and, at the same time, the quality of the work is increased.

To permit a great variety of profiles to be ground, such rotatable profiled presser members are easily exchangeable and rapid and accurate adjustability thereof may be obtained, for example, by means of an eccentric bolt.

An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

FIG. 1 is a schematic elevation of a grinding machine according to the invention;

FIG. 2 is a fragmentary side elevation of the grinding machine, showing partly in section the mounting of a 3,271,907 Patented Sept. 13, 1966 movable presser shoe incorporating a profiled presser member;

FIG. 3 is a side elevation, partly in section and on an enlarged scale, of the presser shoe incorporating the profiled presser member, with the plate springs being removed and seen in the direction of arrow A of FIG. 4, and

FIG. 4 is a cross section taken on the line IV-IV of FIG. 3.

FIG. 1 shows a grinding machine according to the invention, which comprises an endless abrasive band 1 arranged to run about a driving pulley 2 and a guide pulley 3 which are mounted on a supporting beam 4 of the machine frame. The driving pulley 2 is operatively connected with a motor 5a (FIG. 2), and the supporting beam 4 is mounted at its two ends in arms 4a and 4b so as to be rotatable about an axis 4c and is fixable in any desired position by appropriate fixing means such as screws or the like, not shown.

Substantially at midlength of the supporting beam 4, this is provided with an angle arm 5 which serves as a tool holder and on which a presser shoe 6 incorporating a profiled presser member 18 is mounted so as to be movable in the directions indicated by double-arrow B (FIG. 2). For this purpose, the angle arm 5 carries at its free end a cylindrical guide 7 which is preferably inclined in relation to the vertical as can be seen especially from FIG. 2. An angularly bent arm 9 at the upper end of the guide 7 is provided to retain the presser shoe 6 by means of linked joint levers 10 and 11 and through.

rigid and movable intermediate means such as a profiled counter member. The lever 10 is rigidly connected with a lever 12 carrying at its free end a shiftable counterweight 8 provided to apply the required contact pressure to the presser shoe 6. Hinged to the lever 11 is a cross piece 13, and a rod 14 passing through the'guide 7 so as to be slidable therein in the directions of the doublearrow B is secured by one of its ends to the cross piece 13. The range of travel of the rod 14 is adjustable by means of a setscrew 15 threaded through the cross piece 13 and adapted to bear with its free end against a collar-shaped edge of the holding arm 9. A supporting angle piece 14a is rigidly secured by one of its ends to the end of the rod 14 opposite the cross piece 13 and engages with clearance over the abrasive band 1. The other end of the supporting angle piece 14a carries two spaced apart parallel plate springs 16 and 17 which are so designed and arranged that they can hold the presser shoe 6 in a manner permitting a certain movability thereof.

The plate springs 16 and 17 may have, for example, a width of 50 to 70 mm. and a thickness of about 1 mm. and they are particularly adapted to hold the presser shoe 6 always in the same angular position in relation to a workpiece 1a to be ground, the presser shoe being allowed, however, to move parallel to the plane of the abrasive band 1 and vertically of the direction of movement thereof thereby to be accurately adaptable to the profile to be ground in the workpiece 1a.

The plate springs 16 and 17 hold the presser shoe 6 so resiliently that it will always return automatically into its original position without needing any operation or adjustment.

The endless abrasive band 1 adapts itself accurately to the presser shoe 6.

With reference now to FIGS. 3 and 4, the presser shoe 6 is provided with a bore 19 accommodating an eccentric bolt 20. In the region of this bore 19, the body of the presser shoe 6 is provided with a slot 21 so that the eccentric bolt 20 can be clampingly secured by means of a clamping screw 22. In one end face of the eccentric bolt 20, a slot 23 is provided permitting the eccentric bolt 20 to be turned by means of -a screw driver or the like after loosening the clamping screw 22. Owing to the eccentricity of the eccentric bolt 20, which is designated by x in FIG. 4, turning same will result in a displacement of the profiled presser member 18 which is rotatably mounted on two ball bearings 18:: and 1811 at the other end of the eccentric bolt 20. By such a displacement it is possible to bring the profiled presser member 18 into the desired position in relation to slide faces 24 and 25 of the presser shoe 6, Le. into such an advanced position that it projects from a recess 27 in the presser shoe thereby to ensure satisfactory and sharp-edged grinding of a rabbet or the like profile.

Owing to this construction, during the grinding opera tion the abrasive band 1 will be subjected to sliding friction at the slide faces 24 and 25 and to rolling friction at the rotatable profiled presser member 18.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

I claim:

1. In a grinding machine for grinding rabbets and other profiles, of the type including a circulating endless abrasive band having an upper and a lower reach, said abrasive band being guided over pulleys one of which is a driving pulley, the combination of a supporting beam having a presser shoe mounted thereon so as to be movable transversely of the direction of movement of said abrasive band and in a direction parallel to the plane of the upper reach of said abrasive band, and a profiled presser member rotatably mounted in a recess in said presser shoe, said presser shoe engaging under pressure said abrasive band on the side remote from a workpiece thereby to bring said abrasive band into biased contact with a profile to be ground of said workpiece.

2. A grinding machine as claimed in claim 1, wherein the presser shoe is provided with slide faces for engaging the abrasive band and the rotatable profiled presser member is adjustable in relation to said slide faces in the direction in which the contact pressure is exerted.

3. A grinding machine as claimed in claim 2, wherein the rotatable profiled presser member is adjustable in relation to the presser shoe and perpendicularly of the plane of the brasive band.

4. A grinding machine as claimed in claim 3, wherein an eccentric bolt is rotatably mounted in the presser shoe and the profiled presser member is rotatably mount- 1 ed on said eccentric bolt.

5. A grinding machine as claimed in claim 4, wherein the rotatable profiled presser member is mounted on the rotatable eccentric bolt by means of bearings, said eccentric bolt being the axis of rotation of said profiled presser member within the presser shoe.

6. A grinding machine as claimed in claim 5, wherein a clamping screw is provided in the presser shoe for cooperation with the rotatable eccentric bolt, said rotatable eccentric bolt being fixable in any angular position by means of said clamping screw.

7. A grinding machine as claimed in claim 6, wherein the clamping screw forms part of the presser shoe. I

8. A grinding machine as claimed in claim 7, wherein the presser shoe is mounted to be laterally movable thereby to maintain the slide faces of said presser shoe engaging said abrasive band constantly in the same angular position in relation to the workpiece to be ground.

9. A grinding machine as claimed in claim 8, wherein the presser shoe is secured to a holding arm by means of resilient retaining members spaced apart from each other and arranged in parallel relationship.

10. A grinding machine as claimed in claim 9, wherein the holding arm is mounted in a guide so as to be shiftable perpendicularly of the plane of the abrasive band.

11. A grinding machine as claimed in claim 10, wherein an adjustable counterweight is provided on the shift- :able holding arm for biasing said holding arm and thus far applying the required contact pressure to the presser s 0e.

12. A grinding machine as claimed in claim 5, wherein the bearings are antifriction bearings.

13. A grinding machine as claimed in claim 5, wherein the bearings are self-lubricating bearings.

14. A grinding machine as claimed in claim 8, wherein the presser shoe is mounted so as to be laterally movable in parallel relationship to the axes of the pulleys of the abrasive band.

15. A grinding machine as claimed in claim 8, wherein the presser shoe is mounted so as to be laterally and resiliently movable in parallel relationship to the axes of the pulleys of the abrasive band.

16. A grinding machine as claimed in claim 9, wherein the resilient retaining members are plate springs.

References Cited by the Examiner UNITED STATES PATENTS 3,159,949 12/1964 Heesemann 51141 X ROBERT C. RIORDON, Primary Examiner.

LEONARD S. SELMAN, Assistant Examiner. 

1. IN A GRINDING MACHINE FOR GRINDING RABBETS AND OTHER PROFILES, OF THE TYPE INCLUDING A CIRCULATING ENDLESS ABRASIVE BAND HAVING AN UPPER AND A LOWER REACH, SAID ABRASIVE BAND BEING GUIDED OVER PULLEYS ONE OF WHICH IS A DRIVING PULLEY, THE COMBINATION OF A SUPPORTING BEAM HAVING A PRESSER SHOE MOUNTED THEREON SO AS TO BE MOVABLE TRANSVERSELY OF THE DIRECTION OF MOVEMENT OF SAID ABRASIVE BAND AND IN A DIRECTION PARALLEL TO THE PLANE OF THE UPPER REACH OF SAID ABRASIVE BAND, AND A PROFILED 